How to properly reference local resources in HTML?

As it turns out, referencing local resources can be a rub point for some. I'm looking for a canonical answer to local resource referencing, and what they mean.

Take these examples, what is the difference between these reference paths?

• <img src="myfile.png" /> (no leading slash)
• <img src="/myfile.png" /> (with leading slash)
• <img src="folder/myfile.png" /> (no leading slash / in subfolder)
• <img src="/folder/myfile.png" /> (with leading slash / in sub folder)
• <img src="../folder/myfile.png" /> (with dots and a leading slash / in sub folder)

• A leading slash tells the browser to start at the root directory.
• If you don't have the leading slash, you're referencing from the current directory.
• If you add two dots before the leading slash, it means you're referencing the parent of the current directory.

Take the following folder structure

notice:

• the ROOT checkmark is green,
• the second checkmark is orange,
• the third checkmark is purple,
• the fourth checkmark is yellow

Now in the index.html.en file you'll want to put the following markup

<p>
	<span>src="check_mark.png"</span>
	<img src="check_mark.png" />
	<span>I'm purple because I'm referenced from this current directory</span>
</p>

<p>
	<span>src="/check_mark.png"</span>
	<img src="/check_mark.png" />
	<span>I'm green because I'm referenced from the ROOT directory</span>
</p>

<p>
	<span>src="subfolder/check_mark.png"</span>
	<img src="subfolder/check_mark.png" />
	<span>I'm yellow because I'm referenced from the child of this current directory</span>
</p>

<p>
	<span>src="/subfolder/check_mark.png"</span>
	<img src="/subfolder/check_mark.png" />
	<span>I'm orange because I'm referenced from the child of the ROOT directory</span>
</p>

<p>
	<span>src="../subfolder/check_mark.png"</span>
	<img src="../subfolder/check_mark.png" />
	<span>I'm purple because I'm referenced from the parent of this current directory</span>
</p>

<p>
	<span>src="subfolder/subfolder/check_mark.png"</span>
	<img src="subfolder/subfolder/check_mark.png" />
	<span>I'm [broken] because there is no subfolder two children down from this current directory</span>
</p>

<p>
	<span>src="/subfolder/subfolder/check_mark.png"</span>
	<img src="/subfolder/subfolder/check_mark.png" />
	<span>I'm purple because I'm referenced two children down from the ROOT directory</span>
</p>

Now if you load up the index.html.en file located in the second subfolder
http://example.com/subfolder/subfolder/

This will be your output